FDG-PET in Alzheimer's disease

¹⁸F-2-fluoro-2-deoxy-d-glucose (18F-FDG) is a tracer that can objectively evaluate neuronal activity in the brain and has been widely used in the research and diagnosis of Alzheimer's disease (AD). The clinical diagnostic criteria for AD were revised in 2011. Along with magnetic resonance imaging, FDG-positron emission tomography (PET) has been shown to be an important research criteria as an objective biomarker for neuronal injury. Typical FDG-PET findings in AD include reduced glucose metabolism in the parietotemporal association cortex, precuneus, and posterior cingulate. FDG-PET plays an important role in visually and quantitatively perceiving these types of findings; consequently, the certainty of the clinical diagnosis of AD can be improved, and differentiating between AD and non-Alzheimer's dementia is also possible. Furthermore, FDG-PET may be used as a biomarker for early diagnosis of AD, at the mild cognitive impairment (MCI) or preclinical stages, in order to start medical or non-pharmacologic treatment and, subsequently, as a biomarker to determine treatment effects. This chapter focuses on previously collected evidence about the efficacy and practicality of FDGPET in the diagnosis of AD.